Sprocket gear scraping device



H. L.. DENTON sPRocKET GEAR SCRAPING DEVICE April 3, 1945.

Filed Nov. 11, 1942 5 Sheets-Sheet l API 3 1945- H. A|. Dr-:N-roN 2,372,815

SPROGKET GEAR SCRAPING DEVICE Filed Nov. 1l, 1942 5 Sheets-Sheet 3 April 3, 1945. H,

BENTON 2,372,815

SPROCKET GEAR SCRAPNG DEVICE Filed NOV. ll, 1942 s sheetsfsheet 4 April 3, l945 H. L. DENTON. 2,372,815

SPROCKET GEAR SGRAPING DEVICE Filed Nov. l1, 1942 5 Sheets-Sheet 5 Patented Apr. 3, 1945 srnoonn'r GEAR sdRAPINGDEVICE.

Harry L. Denton, Chicago, Ill., assgnor to Wenzel Projector Company, Chicago, Ill., a corporation of Illinois Application November 11, 1942, Serial No. 465,275

(Cl. 9th-1.4)

14 Claims.

This invention relates to a sprocket gear scraping device and, more particularly, to a device for scraping sprocket gears or toothed wheelsof the character which are employed in or as a part of the film advancing mechanisms of motion picture projectors and the like. Y

In the manufacture of sprocket gears, such as those which are used in or as a part of the lm advancing devices of motion picture projectors, burrs or sharp portions remain upon the corners or corner edges of the gear teeth after the latter have been formed and it has been customary heretofore to remove these burrs or sharp portions by means of a manual scraping operation since if they were allowed to remain upon the I sprocket gears they would tear the film vduring ual scraping is, however, a slow and laborious operation and materially adds to the cost of manufacturing sprocket gears of the character hereinbefore referred to and which are used in large quantities,

An object of the present invention is to afford a novel device for mechanically and automatically scraping the corner edges of sprocket gear teeth such, for example, as those which Vare employed in or as a part of the lm advancing devices or motion picture projectors, to remove the burrs or sharp portions remaining thereon after and as a result of the forming or gear cutting or shaping operation, to the end that the cost of manufacturing such sprocket gears or toothed wheels may be reduced and their production materially expedited compared and relative to the prior ari; practice of manufacturing such sprocket gears and which has involved the aforesaid operation of manually scraping the gear teeth embodied therein so as to remove the burrs or sharp portions therefrom.

Another object of the invention is to afford a novel mechanism for mechanically 'and automatically scraping and slightly rounding all of the corners or corner edge portions of the teeth of sprocket gears of the character which are embodied in the lm advancing devices of motion picture projectors and the like so as to prevent the corner edges of the sprocket gear teeth from gradually tearing or cutting the corner :portions of the sprockettooth-receiving openings in the motion picture films with which such sprocket teeth engage.

A further object of the invention is to provide, in combination, in the lnew sprocket gear spaced scraping knives adapted to scrape opposite sides of teeth upon a sprocket gear supportedtherebetween, together with novel means for moving one of the scraping knives into ineifective position after said one scraping knife has completed its normal cycle of operations, that is to say, after it has scraped all of the teeth in an annular row of such teeth upon said sprocket gear, from one side thereof, together with novel means for then moving the other of the said pair of spaced scraping knives into ef` iective position so as by means thereof toscrape all of the said teeth in the said annular row of the same from the opposite side thereof.

An additional object of the invention is` to afford in the new sprocket gear scraping device novel means for supporting a sprocket gear between two spaced scraping knives which are embodied in the invention and in such a man.- ner that said sprocket gear may ybe advanced circumferentially in a step by step movement around and relative to its supporting means during and as an incident to the scraping operation performed thereon yby each of said scraping knives, first in one circumferential direction by one of said scraping knives, and then in the other or opposite circumferential direction by the other of said scraping knives, so as to scrape each of the teeth in an annular row of such teeth from two sides thereof.

`A further object of the invention is to afford in the new sprocket gear scraping device novel means for supporting a sprocket gear, having at least two spaced annular rows of teeth thereon, and said sprocket gear may be moved or advanced circumferentially in a step by step movement, relative to and upon its supporting means, by each of the scraping knives,` during and as an incident to the scraping operation, while being restrained from free rotation upon and relative to said supporting means and in such a manner that after the completion of the scraping operation upon all of the teeth in one of said annular rows Vof teeth upon a sprocket gear, said sprocket gear may be removed from its supporting means and its position thereon reversed so that the teeth in the outer row of said teeth on said sprocket gear may be scraped by said scraping knives.

Another object of the invention is to` provide in the new sprocket gear scraping vdevice novel means for accommodating the throw or extent of movement of each of the scraping knives to sprocket gears of varying pitch, that is to say,

or toothed wheel scraping device, a pair of to use 'upon sprocket gears which differ from scription and claims and will be understood by reference to the accompanying drawings which, by way of illustration, show preferred embodiments of the invention and the principles thereof, and what I now consider to be the best mode in which I have contemplated applying those principles. Other embodiments'of the invention embodying the same or equivalent principles may be used and structural changes may be made as desired by those skilled in the art without departing from the present invention and the purview of the appended claims.

In the drawings,

Fig. 1 is a top plan view of a preferred form of the new sprocket gear tooth scraping device;

Fig. 2 is a side elevational view of the new sprocket gear tooth scraping device as seen from the left-hand side in Fig. 1;

Fig. 3 is an enlarged fragmentary horizontal sectional top plan View on line 3-3 in Fig. 2;

Fig. 4 is a detail view, on line 4-4 in Fig. 3, partly in section and partly in elevation, and illustrating a device for adjusting the scraper knives to impart to them varying throws or orbits or paths of movement so as to enable them to scrape the teeth of sprocket gears in which the teeth are arranged at different or varying distances;

Fig. 5 is a view on line 5-5 in Fig. 1, partly in section and partly in elevation, and illustrating certain of the operating mechanisms embodied in the invention;

Fig. 6 is a view on line 6-6 in Fig. 1, partly in section and partly in side elevation and illustrating a device for controlling the throw or extent of movement of a ratchet advancing pawl and its supporting lever which are embodied in the present invention;

Fig. '7 is a central vertical sectional view on line 1--1 in Fig. 1 and illustrating the construction of the sprocket gear supporting shaft and the arrangement of control cams and advancing mechanism therefor which are embodied in the invention;

Fig. 8 is a view on line 8-8 in Fig. 7, partly in section and partly in side elevation;

Fig. 9 is a fragmentary side elevational view and showing, in full lines, one of the sprocket gear tooth scraping knives in effective position and in the position which it assumes in the initial stage of its cycle of operations and showing, in dotted lines, the same scraping knife raised up out of effective or scraping position;

Fig. 1 0 is a View similar to Fig. 9 but showing the sprocket gear tooth scraping knife which is shown in Fig. 9 in the position which it assumes at a further stage in its cycle of operations;

Fig. 11 is a fragmentary top plan view showing one of the sprocket gear tooth scraping knives, which are embodied in the present invention, in the position which it assumes in the initial stage of its operative cycle in effecting a gear tooth scraping operation;

Fig. 12 is a fragmentary sectional view on line |2|2 in Fig. 11; and

Fig. 13 is a view similar to Fig. 12 but showing the same gear tooth scraping knife which is shown in Fig. 12 in the position which it assumes immediately following the position in which it is shown in Fig. 12.

General A preferred embodiment of the new toothed wheel or sprocekt gear scraping device is illustrated in the drawings and comprises a horizontally extending supporting base I5 upon which a source of power in the form of an electric motor I6 is mounted. The motor I6 has a shaft I1 upon which a pulley I8 is mounted and working around the pulley I8 is a power transmitting member in the form of a V-shaped belt I9. The belt I9 works over a pulley 20 which is carried by a horizontally extending shaft 5l (Fig. 5) which is embodied in and forms a part of the operating mechanism of the new gear tooth scraping device. The operating mechanism of the new sprocket gear tooth scraping device is generally indicated at 2|, (Fig. 5), and is shown as being mounted upon an upwardly or vertically extending supporting member 22 which is mounted upon and carried by the horizontally extending base I5 at one end thereof (Fig. l) and in spaced relationship with the motor I6.

The new sprocket gear tooth scraping device includes a pair of sprocket gear tooth scraping knives 23 and 24, which are shown in Fig. 2, and which are operated by the operating mechanism 2|, in a manner which will be described hereinafter. The sprocket gear tooth-scraping knife 23 is mounted upon and is carried by a supporting arm or carrier 25 and the scraper knife 24 is mounted upon and carried by a supporting arm or carrier 26. scraper knife 23 carried thereby are normally urged downwardly by a spring I3I and the supporting arm 26 and the scraper knife 24 carried thereby are normally urged downwardly by a spring |32. It'will be noted, in this connection, and as shown in Fig. 2, that the upper end portion of the spring |3| is loosely attached to the supporting arm 25 for the scraper knife 23 by means of a U-shaped yoke |43 and that the upper end portion of the spring |32 is loosely attached to the supporting arm 26 for the scraper knife 24 by means of a U-shaped yoke |44, for a reason to be explained hereinafter, the lower end portions of the springs |3| and |32 being anchored to the upright supporting member 22 at the front thereof.

In the use of the new sprocket gear tooth scraping device the gear tooth scraping knives 23 and 24 are moved through a cycle and path of operations in such a manner that they cooperate successively to scrape 'the edge portions and faces of a row of sprocket gear teeth upon sprocket gears such, for example, as the sprocket gears which are embodied in the film-advancing devices of motion picture projectors and the like. To this end the scraping knives 23-25 and 24-26 are alternately lowered and raised out of effective or scraping position under the control of a control device which is particularly shown in Figs. 2, 5, 7 and 8 wherein it is generally indicated at |33.

As shown in Figs. 3, ll, 12 and 13, the gear tooth scraping knife 23 has a notched or indented and sharpened outer end portion 21, which is substantially triangular in plan, and this notched portion 21 of the scraper knife 23 has a beveled foot portion |42 (Figs. 12 and 13) and the gear tooth scraping knife 24 is similarly formed. In the use of the new gear tooth scraping device The supporting arm 25 and the` clically operating the scraping knives 23 and 24,

and for controlling their operation, will now be described.

Sprocket gear supporting device As shown in the drawings, in the use' of the new sprocket gear tooth scraping device, a sprocket gear, such as 29, is mounted upon a horizontally extending supporting shaft or carrier 30 and this supporting shaft 30 has a threaded outer end portion 3l (Fig, '1) upon which a knurled finger grip or knob 32 is mounted. As shown in Fig. '7, the upwardly extending supporting member 22 has a horizontally projecting bearing boss or extension 33 in which a supporting stub shaft 34 is slidably and non-rotatably mounted. This stub shaft 34 has an outer or front end portion 35 which projects into a centrally arranged bearing opening which is formed in a bearing plate 36 which is carried by the upright supporting plate 22. Formed in the outer or front end portion 35 of the stub shaft 34 is a socket 31 and the inner end portion 38 of the sprocket gearsupporting shaft 3D projects into this socket 31. The slidable shaft 34 has an enlarged front end portion 39 that the sprocket gear supporting shaft 30 is detachably keyed to the said enlarged portion 39 of the slidableshaft 34, as at 40, as shown in Fig. 7. Thus it will be seen that the parts 30 and 34 when keyed together, form, in effect, a

single horizontally extending slidable but nonrotatable shaft for supporting a sprocket gear, such as 29, during the operation of scraping the teeth 28 thereon by means of the scraping knives 23 and 24, as will be explained more fully hereinafter.

Carried by and keyed to the bearing portion 33 v of the upright supporting member 22, as shown in Fig. '1, is a stationary disc 4Ia which is keyed to the said bearing portion 33 as at 4Ib. A friction disc or collar 4Il is slidably mounted on the shaft 34 and carries a pin 42 and this pin 42 projects into and Works in a slot 43 which is formed in the shaft 34. A coil spring 44 is mounted upon the shaft 34. This spring 44 bears at its inner end against a reduced portion of the collar 4I and at its outer end the spring 44 bears against a nut 45 which is threaded onto a threaded outer end portion 46 of the shaft 34 and, as may be seen by reference to Fig. '1, the coil spring 44 is retained upon the shaft 34, and its tension thereon may be adjusted by manipulating the adjustable retaining nut 45.

The foregoing arrangement is such that asprocket gear, such as 29, may be inserted or mounted upon the supporting shaft 3l) and secured in position thereon by adjusting the finger grip or nut 32 so as to bind the axially inner end portion of the sprocket gear 29 against the outer surface of the flange 39 on the shaft 34. In this manner the sprocket gear 29 is held upon its supporting shaft 30 in such a manner that the sprocket gear 23 is free to be rotated or advanced circumferentially in a step by step motion, in one direction, by one of the scraping knives 23 or 24, and subsequently in the opposite direction by the other gear tooth scraping knife, While being restrained from rotation upon its supporting shaft 30 by means of the spring 44' and the tension exerted thereby upon the friction disc 4l and, through the latter, upon-the stationary co1- lar or disc 4la. Thus it will be seen that the coil spring 44 and the friction disc 4l and the stationary collar or disc 4|a act as a friction clutch or restraining brake relative to and upon the sprocket gear supporting shaft 30-34.

It will also be noted, in this connection, that the pin and slot arrangement 42-43 permits the sprocket gear ysupporting shaft .3B- 34 to have limited sliding movement in and relative to the upright supporting member 22 and the stationary bearing parts 36 and 33'-4|.

Eccentric scraper knife mounting As best shown in Fig. 2 of the drawings, the supporting arm 25, which carries the sprocket tooth scraping knife 23, includes a bearing portion or sleeve 41 at its inner end and this bearing portion or sleeve 41 has a bearing opening 48 formed therein. An eccentric member works in the bearing opening 48 and this eccentric member 49 is carried by a horizontally extendingV shaft 50 which is journaled in a bearing plate 5l which is mounted upon the upright supporting member 22 at the front thereof (Figs. 2 and 3). This shaft 50 also has a portion which projects, rearwardly of the upright supporting member 22 (Fig. 5) for reasons which will be explained hereinafter.

As shown in Fig. 2, a similar eccentric construction is associated with the gear tooth scraping knife 24, and its supporting arm or carrier 2S, that is to say, the scraper knife supporting arm or carrier includes a bearing sleeve or portion 52 at its inner end and this bearing sleeve or portion 52 has a centrally arranged bearing opening 53 formed therein. An eccentric mem'- ber 54 works in the bearing opening 53 and this eccentric member 54 is mounted upon a horizontally extending shaft 55 which is journaled in a bearing plate 5B which is mountedr upon the upright supporting member 22, at the ,frontl thereof, as shown in Fig. 2. This shaft 55 has a portion which projects rearwardly of the upright supporting member 22, for reasons which will be explained hereinafter.

Scraper knife operating mechanism The operating mechanism for the gear tooth scraping knives 23-25 and 24-26 will now be described, following which the control mechanism, by which the scraping knives 23-25 and 24-26 are alternately loweredv into and raised out of eective or sprocket gear tooth scraping position, will be described.

The operating mechanism for the scraping knives 23-25 and 24-25 includes the horizontally extending drive shaft 51 which is arranged at the rear side of the upright supporting member 22 and which has its end portions journaled in bearing blocks 518 which are attached tothe upright supporting member 22 at the reary thereof (Fig. 5). One end portion of the shaft 51 carries a gear 60 and this gear 60 meshes with a gear 59 which is carried by a vertically extending shaft 6I (Fig. 5). The shaft E! is journaled in bearing blocks 6 2 and 63 which :are mounted upon the upright support 22 at the rear thereof. Similarly, the other endY portion of the shaft 51 carries a gear 65 which meshes with a, gear B4 which is carried Iby a vertically extending shaft 66, and this shaft is journaled in bear- The shaft 6| carries a Worm wheel 69 and this worm wheel 69 meshes with a worm gear 10 which is mounted at the rear of the upright support 22 upon an extension of the shaft 50. Similarly, the shaft 66 carries a worm wheel 1I and this worm wheel 1I meshes with a worm gear 12 which is mounted at the rear of the upright support 22 upon an extension of the shaft 55 (Fig.

Scraper knife control mechanism Formed in the gear 10, upon the rearl side thereof, and as shown in Figs. 5 and 6, is a. radially arranged series of openings or sockets 13a, 13b, 13e, 13d, 13e and 13j, these openings being arranged at varying or different radial distances upon the worm gear 10, for a reason which will be explained hereinafter. selectively insertable into any one of the openings or sockets 13a, to 13j, inclusive, is a, pin or stud |45.

A lever 15 is pivotally mounted between its ends upon the upright, supporting member 22, at the lrear thereof, as at 14, and pivotally mounted upon the lever 15, at 14, is a pawl 16. The pawl 16 is normally urged, by a spring 11, relative to and upon the lever 15, in a direction to engage the teeth of a ratchet 18a., and the lever 15 is urged by a spring 85 (Fig. 5) in a direction to engage the pawl 16 with the ratchet 18a.. As shown in Fig. 5, the spring 85 has one end portion attached to the lever 15, las at 86, and the other end portion of the lever 15 is attached Ito the upright support 22, and at the rear side thereof, as at 81.

As shown in Fig. 1, a second ratchet 18b is also mounted upon the hub 19 of the spacing collar 89 and is keyed to the ratchet 18a as at |36. A latch or holding dog II6 (Figs. 5 and ,8) .is urged by a spring II1 into engagement with the ratchet 18a and the dog IIB restrains the two ratchets 18a and 18h, and associated parts, against retrograde movement upon and relative to the shaft 8I, Fig. 7, and are mounted upon a hub portion 19 of the spacing disc or collar 80 which `is rotatably mounted upon a stub shaft 8|. As best shown in Fig. '1, the stub shaft 8| has an end portion 82 which is mounted in a socket formed in a bearing plate 83. The bearing plate 83 is lmounted upon the upright suplporting member 22 at the rear side thereof, and the stub shaft 8| is keyed to a hub portion of the bearing plate 83 as at 8f4A (Fig. 7)

Likewise mounted upon the stub shaft 8| (Fig. '1) is a spacing collar |05 and this spacing collar |05 is keyed to the spacing collar 80, as at |31. The spacing collar |05 has a hub portion |06 and mounted upon this hub portion |06 of the spacing collar |05 are a pair of mutilated cams |01 and |08 which are separated by a spacing disc |38. The two cams |01 and |08 and the spacing disc |38 therebetween are keyed togetherjas at |30, and these parts are retained upon the shaft 8| by means of a nut |39 which is threaded onto a threaded outer end portion of the hub |06 of thespacing colla-r |05. i

The purpose and function of the cams |01 and |08 and of the ratchets 18a and 18h, and associated parts, including the cam 'followers which are associated with the cams |01 and |08. will be described hereinafter.

A bearing plate or bracket 88 is attached to the upright supporting member 22, above the worm gear 10, as shown in Fig. 5, and a shaft 89 extends through an opening formed in the upright supporting member 22, 'and has its rear end portion journaled in the bearing plate or bracket 88.

The shaft 89 has a front end portion which projects forwardly of the upright supporting member 22 and carries a link 90 and this link 90 is pivotally connected as at 9|, to a depending arm 92. A laterally or forwardly extending stud or pin 93 is' mounted' upon the lower end portion of the arm 92 and this stud or pin 93 projects under the outer end portion of the carrier or supporting arm 25 for the scraper knife 23, as shown in Fig. 2. A pair of guide pins |03 and |04 are associated with the depending arm 92, these guide pins |03 and |04 being mounted in the upright supporting member 22, at the front thereof, and upon opposite sides of the depending arm 92 (Fig. 2).

A bearing plate or bracket 94, similar to the .bearing plate or bracket 88, is attached to the upright supporting member 22, at the rear thereof, and above the worm gear 12. A horizontally extending shaft 95 projects through an opening formed in the upright supporting member 22 and has its rear end portion journaled in the bearing plate 94. This shaft 95 also includes a portion which projects forwardly of the upright supporting member 22and carries a link 96, and this link 96 is pivotally connected, as at 91, to a depending arm 98 (Fig. 2). A laterally projecting stud or pin 99 is mounted upon the lower end portion of the depending arm 98 and this stud 99 projects under the outer end portion of the carrier member or supporting arm 26 for the scraper knife 24, as best shown in Fig. 2. The arm 98 is guided during its movement, which will be described hereinafter, by means of a pair of spaced guide pins |00 and I0| which are mounted upon the upright supporting member 22, at the front thereof, and which are similar to the guide pins |03 and |04 which are associated with the arm 92.

The construction and mounting of the cam followers associated with the cams |01 and |08 will now be described.

Mounted upon the shaft 89, rearwardly of the upright supporting member 22, and fast to the shaft 89, is an arm |09 and this arm |09 carries a cam roller or follower |I0 which rides upon the peripheral edge and cam surface of the cam |08, as shown in Figs. 1, 5 and 8.

Similarly, an arm `I Il is mounted upon the shaft 95, rearwardly of the upright supporting member 22, and this arm I I| carries a cam roller or follower II2 which rides upon the peripheral edge and cam surface of the cam |01, as shown in Figs. l, 5 and 8. 'Ihe peripheral edge and cam surface of the cam |01 is provided with an interf rupted or cut-out portion |I3 and the peripheral edge and cam surface of the cam |08 is provided With a similar interrupted or cut-out portion I I4, for reasons which will be explained hereinafter.

M anual starting device Y A manually operable starting lever |I8 is mounted upon the shaft 95, at the front of the upright support 22. The lever II8 is guided in a guiding element II9 and has an angled end portion which is provided with a manually operable portion or key |20'. The lever ||8 also has an upwardly extending inner end portion or arm |2I and provided in the arm I2I is aslot |22. A lever |24 is pivotally mounted, between its ends, as at |25, upon the top wall of the upright supporting member 22, and this lever |24 has an arm |23 which projects into and works in the slot |22 which is formed in the upwardly extending arm I2I of the manually operable lever I I8, as shown in Figs. i and 2. Mounted upon the lever |24 is an upwardly extending pin |26 upon which a coil spring |40 is mounted (Figs. 2 and 8). A paw] |21 is pivotally connected to the pin |26, below the coil spring |49, andthis pawl |26 has a bifurcated portion |2`|a (Fig. 1) which engages with the teeth of the ratchet 18a.. A spring |28 has one end portion attached to the pin |26 on the lever 24, and the other end portion of this spring |28 is anchored, as at |29, in the upper edge portion of the upright supporting member 22.

The ratchet 18a has a. mutilated or interrupted portion in the form of a smooth surface |4| upon its peripheral edge and the purpose of which will be described hereinafter.

Operation of the scraper knives A sprocket gear, such as 29, may be -mounted upon the supporting'shaft 30-34, and so as to be rotated relative thereto, by first loosening the key 40, then removing the knurled nut 32 from the threaded outer or front end portion 3| of the shaft 3D, inserting the sprocket 29 upon the sha-ft 39, inserting the inner end portion 38 of the shaft 39 in the socket 31 which is formed in the shaft 34, tightening the key 40 so as to key the two parts 39 and 34 of the shaft 30--34 together, and then tightening the knurled nut 32, upon the shaft 30. against the action of the spring 44. When thus mounted upon the shaft 39-34 the sprocket gear 29 is free to be turned or rotated circumferentially in a step by step motion upon and relative to the shaft 38-34 by means of, and under the action of, the scraper knives 23-25 and 24-26, in a manner which will be described presently, while, at the same time, the spring 44 and the friction disc 4| and the stationary disc 4|a coopcrates to exert a braking action upon the shaft Bil- 34 to prevent rotation of the shaft SI1-34 with the sprocket gear 29.

The motor |6 may then be set in operation, whereupon power is transmitted from the motor I6, through the motor shaft I1, V-shaped pulley i8, V-shaped belt |9, and V-shaped pulley 20, to the shaft 51. Power is transmitted from the shaft 51 by way of the gears 69 and 59, shaft 6|, and gears 69 and 'I9 to the shaft 50 upon which the carrier or supporting arm 25 for the gear tooth scraper knife 23 is mounted, so as to operate the scraper knife 23.

At the same time power is transmitted from the shaft 5'! by way of the gears 65 and 64, shaft 66, and gears and '|2 to the shaft 55 upon which the carrier or supporting arm 29 for the gear tooth scraper knife 22 is mounted,so as to operate the scraper knife 24.

It will thus be seen that the shafts 5|! and 55 are rotated simultaneously but in opposite directions, that is to say, the'shaft 5|! is rotated in a counterclockwise direction, as seen in Fig. 2, while the shaft 55 is rotatedin a clockwise direction as seen in the same figure.

When the shaft 50 is rotated in a clockwise direction, as seen in Fig. 2, an eccentric motion is imparted, by way of the eccentric member 49 and the eccentric bearing portion or opening 48 which is formed in the sleeve 4l of the supporting arm 25, to the supporting arm or carrier 25 and to the gear tooth scraper knife 23 carried thereby.

.Similarly, when the shaft 55 is rotated in a clockwise direction, as seen in Fig. 2, an eccentric motion is imparted to the supporting arm 26 and to the scraper knife 24 carried thereby, by means of the eccentric member 54 and the bearing opening 53 which is formed in the sleeve portion 52 Of the supporting arm 26.

As'shown in Fig. 2, when the scraper knife 23 and its supporting arm or carrier 25 are disposed in lowered or effective position, that is, in position for the scraper knife 23 to engage successively the teeth 28 in the inner row of teeth upon the sprocket gear 29, the other scraper knife 24 and its supporting arm 26 'are in raised or ineffective position, that is to say, out of position for the scraper knife 24 to engage the teeth 28 in the inner row of teeth 28 upon the sprocket gear 29.

As best shown in Figs. 9, 10, 11, 12 and 13, when an eccentric motion is thus imparted to the scraper knife 23 and its supporting arm 25, the path of movement of the scraper knife 23 is such that during the rs't part of its movement or normal orbital cycle of operation it moves somewhat downwardly,` from dotted to full line position, Fig. 9. The scraper knife 23 and its supporting arm 25 then move laterally from the position in which they are shown in full lines in Fig. 9 into the position in which these parts are shown` in full lines inFig. 10. During this motion of the scraper knife 23 the flattened base or foot |42 of the notched or indented outer end portionrZ'l thereof bears upon the peripheral surface of the sprocket gear 29, in the space between two of the gear teeth 28 which are arranged in the inner row of gear teeth 28 upon the sprocket 29, and with one of the teeth 28 inthe notch 21, as shown in Figs. 11 and- 12.

The orbit or path of movement of the scraper knife 23 is such that as its beveled foot portion |42 moves into engagement with the peripheral surface 28a of the sprocket gear 29, in the space between two adjacent sprocket teeth 28, the scraper knife y23 moves laterally from the position in which 'it is shown in full lines in Fig. 9 into the position in which it is shown in Fig. 10, 0r from the position in which it is shown in Figs. 11 and 12, -into the position in which it is shown in Fig. 13. During this movement of the scraper knife 23, the notched end portion 2'| thereof engages at the base 28a of the tooth 28 and moves the sprocket gear 29 in a counterclockwise direction (Fig. 12).

As the scraper knife 23 moves laterally from the position in which it is shown in full lines in Fig. 9 into the position in which it is shown in Fig. 1 0, or from the position Iin which it is shown in full lines in Figs. 11 and 12, into the position in which it is shown in Fig. 13, it advances or moves the sprocket gear 29, upon the shaft 3|]- 34, one circumferential step, in a counterclockwise direction as seen in Figs, 2, 9 and 13, and during and as a resultof this movement the next succeeding or following gear tooth 28 moves under the outer and sharpened end portion of the scraper knife 23 and raises the outer and sharpened end portion thereof, against the action of the spring |3I, from the position 4in which the outer and sharpened end portionof the scraper knife 23 is shown in Figs. 11 and 12 into the position in which it is 'shown in Fig. 13. During this upward movement of the scraper knife 23, the notched or yindented knife portion 2'| thereof engages the two corner edges 28e and 28d of the tooth .28 (Fig. 11), and rides up the face 28hof the tooth 28, thus scraping and slightly roundknife 23 and its supporting arm 25 then move laterally, from left to right as seen in Figs. 10 and 13, back into the position in which these parts are shown in Fig. l0, whereupon the scraper knife 23 and its supporting arm 25 again move downwardly and then again laterally, from right to left, as seen in Figs. 9 and 12, and into engagement with the next succeeding or following gear tooth 28, to effect the next cycle of operations. This cycle of operations is repeated until the corners or corner edge portions of all of the gear teeth 28 which are included in the inner row of such teeth 28 upon the sprocket gear 29 have been scraped and slightly rounded by means of the scraper` knife 23 so that they will not tear those portions of motion picture films which dene the marginal edge or corner portions of the sprocket tooth-receiving openings in such motion picture lms and in which such sprocket teeth may engage in use.

Each time the scraper knife 23 moves through its normal cycle of operations, and each time the shaft 50 travels through one revolution to cause the scraper knife 23 to complete a scraping operation, the stud or pin |45, which is arranged in, and frictionally held in, the socket 13e of the gear 10, engages the lower end portion of the lever 15, as shown in Figs. and 8, thereby pivoting the lever 15, at 14, against the action of the spring 85, and in a, counterclockwise direction as seen in Fig. 5. This movement of the lever 15 causes the spring held pawl 16, which is carried thereby, to engage the ratchet 18a, thus advancing the ratchet 18a, the ratchet 18D, the spacing collars 80 and |05, and the cams |01 and |08, one circumferential step around and relative to the fixed or stationary supporting shaft 8|, upon which these parts are mounted, it being understood that all of these parts are keyed together into a unitary structure, as indicated at |36, |31, and |30 in Fig, 7. During this operation these parts are held against retrograde movement by the engagement of the dog I I6 with the teeth of the ratchet 18h. This operation is continued until the ratchet 18a, the ratchet 18, and the cams |01 and |98 have completed one revolution upon and relative to their supporting shaft 8|, whereupon the pawl 16 engages in the mutilated or smooth surface portion |4| which is formed upon the peripheral edge of the ratchet 18a., said mutilated or smooth peripheral edge portion |4| of the ratchet 18a being best shown in Fig. 8.

' As the cams |01 and |08 are thus moved, step by step, around and relative to the shaft 8|, under the action of the'stud |45, lever 15, pawl 15, and ratchet 18a, the cam follower or roller 2 upon the arm rides over the peripheral edge or cam surface of the cam |01 and the cam follower or.roller ||0 on the arm |09 rides over the peripheral or cam Surface of the cam |08. This motion of the ratchet`18a, as well as the ratchet 18h, and of the cams |01 and |08 is, however, interrupted when the pawl 16 engages the smooth or interrupted portion |4| which is formed upon the peripheral edge of the ratchet 18a and, when this occurs, the cam follower ||0 upon the arm |09 rides up out of the mutilated portion ||4 of the cam |03 and onto the rise of this cam |08. This motion of the cam follower I0 acts, through the arm |09, and the shaft 89, to rock* the shaft 89 and the link 90, in a clockwise direction, as seen in Fig. 24, thereby raising the arm 92, which is carried by the link 90. As the arm 92 is thus raised the laterally projecting stud or pin V93,

whichis carried thereby,engages under the supporting arm or carrier 25 for the scraper knife 23, and thus lifts the scraper knife 23 and its supporting arm or carrier 25, against the action ofthe spring |3|, into raised or ineffective position, thus placing the spring |3| under tension. During this upward movement of the arm 92 the same is guided by and between the guide pins |03 and |04, as shown in Fig. 2.

Atthe time when the cam follower ||0 rides up onto the rise of the cam |08, to effect movement of the scraper knife 23 into raised or ineffective position, the scraper knife 24 is still in raised or ineffective position, as shown in Fig. 2, and at this time the cam follower ||2 is in engagement with the rise of the cam |01.

Hence, it will be seen that at this time in the cycle of operations ofthe new gear tooth scraping device both of the scraper knives 23 and 24 are in raised or ineffective position and movement'of the operating mechanism for the scraper knives 23 and 24 merely imparts an idling motion to the scraper knives, and during this idling motion the scraper knives 23 and 24 and their supporting arms 25 and 25, respectively, slide upon the laterally projecting pins or studs 93 and 99, respectively. It will be noted, in this connection, during this idling motion of the scraper knives 23 and 24 and their supporting arms 25 and 26, respectively, these parts slide through the yokes |43 and |44, respectively, by which the upper end portions of the springs |3| and v|32 are loosely attached to the supporting arms 25 and 25 for the scraper knives 23 and 24, respectively.

With the scraper knives 23 and 24 thus both disposed in raised or ineffective position, further effective operation of the new gear tooth scraping device, and of the scraper knife 24, is effected as follows: To initiate further operation of the device, at this point in its normal cycle of operations, the manually operable key |20 and its supporting lever ||8 are depressed and this motion rocks the lever ||8 about its pivot, the shaft 95, thereby rocking the upwardly extending and slotted arm 2| 0f the lever ||8 in a counterclockwise direction as seen in Fig. 2. This movement of the upwardly extending and slotted arm |2| of the lever ||8 acts to pivot the lever |23-|24, at |25, in a clockwise direction, as seen in Fig, 1. This movement of the lever |24 moves the bifurcated portion |21a of the pawl |21 into engagement with the teeth of the ratchet 18a, thus stepping the ratchet 18a., the ratchet 18h, and the two cams |01 and |08, and associated parts, one circumferential step around and re1- ative to their supporting shaft |8I, and thereby moving the smooth or mutilated portion |4| of the ratchet 18a past the pawl 16 so that the pawl 16 again engages with the teeth of the ratchet 18a.

At this time the cam follower l2 rides down off from the rise of the cam |01 and into the cut-out ormutilated portion ||3 of this cam, and this movement of the cam follower ||2 causes the then tensioned spring |32 to exert a downward pull upon the supporting arm 26, and the scraper knife 24 carried thereby; this downward .movement of the supporting arm 26 and the scraper knife 24 carried thereby acting, through the stud 99 to rock the arm 98, the link 96 and the shaft 95, the arm and the cam follower 2 carried thereby, in a clockwise direction, as seen in Fig. 2, thus lowering the scraper knife 24 and its supporting arm 26 into effective position.

During this downward movement the arm 98 is guided by and between the guide pins and |0l, (Fig. 2).

Accordingly, when the scraper knife 24 has thus been moved downwardly into lowered or effective position, and as the operation of the new gear tooth scraping device continues, the scraper knife 24 successively engages each of the teeth 28 which are included in the inner row of teeth 28 upon the sprocket gear' 29, and which have been previously scraped by the scraper knife 23, and successively scrapes the two corner edges 28e and 28j of each of these teeth 28 which are opposite and complementary to the two corner edges 28e and 28d Fig- 1l) of each of said teeth 28 which have previously been scraped by the scraper knife 23.

During this movement the sprocket gear 29 is advanced in a circumferential or step by step movement, upon and relative to the supporting shaft lio-3ft, and in a clockwise direction as seen in Fig. 2, and after one complete revolution of the sprocket gear 29, the advancing pawl 'I6 again engages the mutilated or smooth peripheral edge portion I 4| of the ratchet 73a, thereby again stopping. the operation of the ratchet 18a, the ratchet i812, and the cams |91 and Hi8 and associated parts. As this time the cam follower ||2 upon the arm rides up out of the mutilated portion H3 of the cam im and onto the rise of this cam, thus rocking the shaft 95'and the link 96, in a counterclockwise direction, as seen in Fig. 2. This movement of the shaft 95 and the link 96 acts, through the arm 98 and the laterally projecting pin or stud 99 which is carried thereby, to raise the supporting arm 26 and the scraper knife 24 which is carried thereby, against the action of the spring |32, into raised. or ineffective position, thus completing a cycle of operations of the new sprocket gear tooth scraping device.

The retaining nut 32 may the-n be removed from the sprocket gear supporting shaft 30-34, whereuponthe position of the sprocket gear 29 upon the shaft di! may be reversed, thus mow'ng the other or second and previously outer row of gear teeth 28 upon the sprocket gear 29 into a position in which .each 0f the teeth therein may be scraped successively by the scrap-ing knives 23 and 24. The operation of the new gear tooth scraping device may then bel initiated, and the hereinbefore described cycle of operations may be repeated, by depressing the manually operable starting lever I I8 through its key |20.

Adjustment for sprocket gears of omg/ing pitch By reference to Figs. 3 and 4, it will be noted that the shaft i! has an enlarged and discshaped portion |33 which is arranged between the bearing or bracket plate 5| and the supporting arm or carrier 25 for the scraper knife 23, as shown in Fig. 3. The disc-shaped portion |33 of the shaft 50 is provided with a radially arranged row of sockets or recesses |34. Carried by the eccentric member 49, is a pin |35 which is selectively insertable into any one of the recesses or sockets |34 in the disc-shaped portion |33 of the shaft 59, and may be held therein by the retaining nut |45 which is mounted upon a threaded outer end portion |4841 of the shaft 50, as shown in Fig. 3. This arrangement enables the eccentric member 49' to be adjusted upon and relative to the shaft 52 so as to vary the throw or extent of movement of the supporting arm or carrier 25 and the scraper knife 23 carried thereby so as to accommodate the throw or extent of movement of the scraper knife 23 to sprocketV gears of varying pitch.

, A construction identical to that just described is associated with the shaft 55, and the eccentric device 53-54 which cooperates therewith, so as to enable adjustment of the throw or extent of movement of the scraper knife 24 and its supporting arm 26 to sprocket gears of varying or different pitch. f

It will also be noted, by reference to Figs. 5 and 6, that the recesses or sockets 13a, 13b, '|3c, 13d, 13e and 13j are arranged at different or varying radial distances in and relative to the gear 70, and that the pin or stud |45 is selectively insertable into any one of the sockets 13a to 73j, inclusive, wherein it may be held by frictional engagement or otherwise.

.As will -be seen by reference to Figs. 5 and 6, the throw of the lever 15 and of the ratchet-advancing pawl 16 carried thereby may be controlled and varied by positioning the stud |45 in any selected one of the sockets or recesses '13a to l3f, inclusive, which are formed in thegear k'||l, that-is to say, the position of the stud |45 upon and relative to the gear 10, and its radial distance from the shaft 50, controls the extent of movement or the throw of the lever 'l5 and the pawl 16 and thus determines the circumferential distance which the pawl 'I6 will advance the ratchet 78a, the ratchet 18h, the cams |91 and' |08, and f associated parts. at each operation of the' lever 15 and the pawl 16 carriedthereby. Hence, it will be seen that this construction and arrangement enables the new sprocket gear tooth scraping device to be adjusted for use in conjunction with sprocket gears of varying pitch.

It will also be understood and appreciatedin this connection, that the shape or configuration of the notched or indented and sharpened outer end portions 21 of the scraper knives 23 and 24 may be varied to accommodate these parts to sprocket gear teeth of varying configurations or shapes and of Varying heights or depths.

It. will be understood that the arrangement of the motor I6, power transmitting mechanism I'|-|8-|92|J5'|, and operating mechanisml 2|, and other parts of the new gear tooth scraping device, affords a compact, unitary and portable structure. It will be understood, however, that within the scope and contemplation of the present invention the motor |6, power transmitting mechanism |`||8|920-5'|, and associated parts may all be arranged as a permanent installation upon any suitable supportingv base and that the new gear tooth scraping device need not necessarily be constructed as a portable unit, as shown.

It will thus be seen from the foregoing description, considered in conjunction with the accompanying drawings, that the present invention affords a novel device for mechanically and automatically scraping sprocket gears such,.for example, as those which are used in the filmadvancing mechanisms of motion picture projectors, and the like, and thus accomplishes its intended objects including those which have been specicially pointed out hereinbefore, as well as others which are inherent in the invention.

I claim:

l. A sprocket gear scraping device comprising, in combination, means for supporting a sprocket gear, an elongated and substantially flat scraper knife having a notched knife edge portion, means for supporting said scraper knife, and means co-A operating witn said supporting means for said scraperknife for moving the said notched knife edge portion thereof generally tangentially of the gear along edge portions of each of the teeth of said sprocket gear so as to exert a scraping action simultaneously on both of said two edge portions of a vgear tooth during each gear tooth scraping operation. v

2. A sprocket gear scraping device as defined in claim l in which the said notched knife edge portion of said scraper knife is substantially triangular in shape and is adapted to engage and scrape two corner edge portions of one of the teeth of said sprocket gear during each scraping operation.

3. A sprocket gear scraping device as defined in claim 1 in which the said notched knife edge lportion of said scraper knife is substantially triangular in shape and is adapted to engage and scrape two corner edge portions of one of the teeth of said sprocket gear during each scraping operation, and in which said sprocket gear scraping device the said notched portion of said scraper knife is raised or lifted upwardly relative to and in engagement with a tooth upon said sprocket gear during each scraping operation, and against the action of a spring, by means of the next succeeding or adjacent tooth upon said sprocket gear following the tooth upon which the scraping operation is being performed.

4. A sprocket gear scraping device as defined in claim 1 in which the said notched knife edge portion of said scraping knife has a beveled bottom edge which is adapted successively to engage and bear upon the peripheral surface of said sprocket gear at the base of each of the teeth thereon at one stage in the operation of said scraping knife upon each of said teeth.

5. A sprocket gear scraping device, comprising, in combination, a pair of sprocket gear tooth scraping knives, means for supporting a sprocket gear between said scraping knives, means for moving one of said scraping knives successively into engagement with each of the teeth in an annular row of teeth upon a sprocket gear supported by the said sprocket gear supporting means between said scraping knives so as to effect a scraping action upon each of the said teeth at one side thereof, and means for then successively moving the other of said scraping knives into engagement with each of the teeth in the said an# r nular row of teeth upon said sprocket so as to effect a scraping operation upon each of the said teeth at the side thereof which is opposite to the side of said teethwhich has been scraped by the said one of said scraping knives.

6. A sprocket gear scraping device as defined in claim 5 which includes means for automatically moving the said one of said scraping knives into ineffective position, that is, out of position to engage the teeth upon said sprocket gear after the said one of said scraping knives has completed a scraping operation upon each and all of thc teeth in said annular row of the same, and which said sprocket gear scraping device includes means for then moving the other of said scraping knives into effective position, that is, into position successively to engage each of the said teeth in the said annular row of the same upon said sprocket gear so as toA eiect a scraping operation thereon.

'1. A sprocket geai' scraping device as defined in claim 5 which includes means for automatically moving the said one of said scraping knives into ineffective position, that is, out of position to engage the teeth upon said sprocket gear after the said one of said scraping knives has completed a scraping operation upon each and all of the teeth in said annular row of the same, and which said sprocket gear scraping device includes means for then moving the other of said scraping knives into effective position, that is, into position successively to engage each of the said teeth in the said annular row of the same upon Said sprocket gear so as to effect a scraping operation thereon, and in which said sprocket gear scraping device the said means for moving the said other of said scraping knives into effective position includes a manually operable device for initiating movement of said other scraping device into effective position.

8. A sprocket gear scraping device as defined in claim 5 in which the said sprocket gear supporting means includes means enabling a sprocket gear supported thereby to be removed therefrom andits position thereon reversed axially of said sprocket gear after the said one of the said scraping knives has completed a scraping operation upon each of the teeth in an annular row of teeth upon said sprocket gear so that the teeth in another annular row of such teeth upon said sprocket gear may be disposed in position to be scraped by the said other one of said Vscraping knives.

9. A sprocket gear scraping device as defined in claim 5 which includes means for adjusting the throw or extent of movement of each of said scraping knives so as to accommodate the throw or extent of movement of each of the said scraping knives to different sprocket gears having teeth of varying or different pitch.

10. A sprocket gear scraping device comprising, in combination, means for supporting a sprocket gear, a scraper knife, means for supporting said scraper knife, means cooperating with said supporting means for moving said scraper knife successively into engagement with the teeth of a sprocket gear supported by said supporting means while at the same time imparting a circumferential or step by step movement to said sprocket gear relative to and upon said supporting means during and as an incident to each scraping operation, said sprocket gear scraping device including means for adjusting the throw or extent of movement of the said scraper knife so as to accommodate the throw of the said scraper knife to different sprocket gears having gear teeth of varying or different pitch.

11. A gear tooth scraping device specifically adapted for use in scraping the teeth of a gear of the type which embodies an annular row of circumferentially spaced gear teeth, and in which each of said gear teeth includes a tooth face having a pair of corner edges formed by the intersection of the said tooth face with the side walls of the said gear tooth, a notched scraping means, means for supporting said scraping means, means cooperating with said supporting means for the scraping means for moving the scraping means generally tangentially of the gear, means for supporting said gear, the scraping means adapted for simultaneous engagement and scraping along both of the said corner edges of the said gear tooth face during and as a part of a single scraping operation, and means for operating said scraping means to effect a simultaneous scraping action along both of the said corner edges of the gear tooth during each gear tooth scraping operation.

12. A gear tooth scraping device as defined in claim 11 which includes means for accommodating the movement of said gear tooth scraping means to gear teeth of varying or diierent pitch.

13. A gear tooth scraping device as defined in claim 11 in which the said scraping means comprises an elongated substantially nat scraper knife having one end thereof in the form of a notched scraping edge which is adapted to scrape both of the said corner edges of the said gear tooth simultaneously during each scraping Operation.

edge which is adapted to scrape both of the said corner edges of the said gear tooth simultaneously during each scrapingoperation, and in which said gear tooth scraping device includes an eccentric mounting mechanism for supporting said scraper knife and means cooperating with the said eccentric mounting mechanism for varying the throw and orbit of movement of said scraper knife so as to accommodate said scraper knife to gear 14. A gear tooth scraping device as dened in 10 teeth of varying or different pitch.

claim 11 in which the said scraping means comprises a scraper knife having a, notched scraping HARRY L. BENTON. 

